The present invention relates to disposable pull-on wearing articles such as for example, diapers.
Unexamined Japanese Patent Application Publication No. 2002-153503 (thereinafter referred to as “Citation 1”) discloses a disposable diaper including a backsheet made of light transmissive plastic film and an indicator means adapted to be visually recognized from the outside of the backsheet.
Unexamined Japanese Patent Application Publication No. 2002-657 (hereinafter referred to as “Citation 2”) discloses a pull-on disposable diaper having a backsheet comprising a film printed on its outer surface with an image and a nonwoven fabric laminated on the outer surface of the film wherein the nonwoven fabric has a light transmission in a range of 40 to 83%.
For the diaper disclosed in Citation 1, the backsheet preferably comprises a plastic film having a sufficiently high light transmission to facilitate the indicator means to be visually recognized from the outside of the backsheet and an appropriate light diffusivity to prevent the body liquid absorbent core lying inside the backsheet from seen through the backsheet. However, the plastic film meeting such requirements may often result in an unacceptably thin film which may be readily broken.
For the diaper disclosed in Citation 2, in order that the image can be seen clearly from the outside of the backsheet, the nonwoven fabric preferably has a sufficiently small basis weight to improve the light transmission of the nonwoven fabric. However, such nonwoven fabric also may result in an unacceptably thin nonwoven fabric which may be readily broken.
As the backsheet for the diaper disclosed in Citation 1 or Citation 2, it is well known to use an elastically stretchable nonwoven fabric or a plastic film made of plastic elastomer or an elastically stretchable nonwoven fabric made of crimped fibers. However, the nonwoven fabric or the plastic film made of plastic elastomer generally has a relatively low light transmission. In such a case, to facilitate the display element such as indicator means or image to be visually recognized from the outside of the backsheet, a film printed with the display element is preferably bonded to the inner surface of the backsheet as thin as possible by means of adhesive or heat-sealing technique. However, such backsheet is disadvantageous in that the region in which the film has been bonded to the backsheet may be affected by a stress concentrating in this region and be broken therein as the backsheet is stretched in a waist-surrounding direction. The backsheet formed from a nonwoven fabric made of crimped fibers inevitably become bulky and, in order to facilitate the display element to be visually recognized from the outside of such backsheet, it is preferred to use the backsheet as thin as possible. However, in this case also, the backsheet is apt to be broken in the region thereof in which the film printed with the indicator element has been bonded to the backsheet.